Piperidine compounds containing silane groups for use as stabilisers for organic materials

ABSTRACT

The present invention relates to novel piperidine compounds of the formula (I) ##STR1## in which A is e.g. a group of the formula ##STR2## where R 4  is e.g. hydrogen or methyl, X 3  is e.g. --O-- or --NH-- and R 5  &#39; is e.g. ethylene, propylene or decamethylene, R 1  is e.g. methyl, methoxy, ethoxy or OH, R 2  and R 3  are e.g. methyl, m+n is e.g. a number from 1 to 40, n varies e.g. from zero to 50% of the sum m+n, X 1  is e.g. as defined for R 1  or is a group (CH 3 ) 3  SiO-- and X 2  is e.g. hydrogen, methyl, ethyl, a group (CH 3 ) 3  Si-- or a group ##STR3## and, when m+n is a number from 3 to 10, X 1  and X 2  together also form a direct bond. The compounds of the formula (I) are effective in stabilising an organic material against thermal, oxidative and light-induced degradation.

The present invention relates to novel piperidine compounds containingsilane groups, to their use as stabilisers for organic materials, inparticular synthetic polymers, against light, heat and oxidation, and toorganic materials thus stabilised.

The use of 2,2,6,6-tetramethylpiperidine derivatives containing silanegroups, such as those reported in U.S. Pat. Nos. 4,177,186 and4,859,759, EP Laid Open Prints Nos. 162 524, 182 415, 244 026, 263 561,343 717 and 358 200 and DD Patents Nos. 234 682 and 234 683, asstabilisers for synthetic polymers is known.

The present invention relates to novel compounds of the general formula(I) ##STR4## in which A is one of the groups of the formulae (IIa)-(IId)##STR5## in which R₄ is hydrogen, C₁ -C₈ alkyl, O., OH, NO, CH₂ CN, C₁-C₁₈ alkoxy, C₅ -C₁₂ cycloalkoxy, C₃ -C₆ alkenyl, C₇ -C₉ phenylalkylwhich is unsubstituted or mono-, di- or tri-substituted on the phenyl byC₁ -C₄ alkyl; or C₁ -C₈ acyl, X₃ is --O-- or >N--R₁₂ where R₁₂ ishydrogen, C₁ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted ormono-, di- or tri-substituted by C₁ -C₄ alkyl; C₇ -C₉ phenylalkyl whichis unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄ alkyl; or tetrahydrofurfuryl, C₂ -C₄ alkyl substituted in the 2-, 3-or 4-position by C₁ -C₈ alkoxy, by di-(C₁ -C₄ alkyl)-amino or by a groupof the formula (III) ##STR6## where X₄ is a direct bond, --O--, --CH₂--, --CH₂ CH₂ -- or H₃ C--N<, or R₁₂ is a group of the formula (IV),##STR7## with R₄ as defined above, or R₁₂ is one of the groups of theformulae (Va)-(Vd) ##STR8## where R₄ is as defined above, X₅ is --O-- or>N--CH₃ and X₆ is --CH₂ CH₂ --, --CO--, --COCO-- or --COCH₂ CO--, or X₃is a 1,4-piperazinediyl group, p is 1, 2 or 3 and, when p is 1, R₅ is C₂-C₁₈ alkanediyl and, when p is 2, R₅ is C₂ -C₂₀ alkanetriyl, C₅ -C₇cycloalkanetriyl or C₇ -C₉ bicycloalkanetriyl or a group ##STR9## whereX₇ is --O-- or >N--R₁₄ with R₁₄ being C₁ -C₈ acyl or (C₁ -C₈alkoxy)carbonyl, R₁₃ is C₃ -C₁₂ alkanediyl and q is 0 or 1, and, when pis 3, R₅ is C₃ -C₆ alkanetetrayl, R₆ is as defined above for R₁₂, R₇ isC₂ -C₁₂ alkanediyl, R₈ is hydrogen or methyl, R₉ is a direct bond, C₁-C₁₈ alkanediyl or a group --X₇ --R₁₃ -- with X₇ and R₁₃ as definedabove, R₁₀ is hydrogen or methyl and R₁₁ is --CH₂ -- or --CH₂ CH₂ --, R₁is C₁ -C₈ alkyl, phenyl, C₁ -C₈ alkoxy or OH, R₂ and R₃ which areidentical or different are C₁ -C₈ alkyl or phenyl, or R₂ is alsohydrogen, m+n is a number from 1 to 100, n varies from zero to 90% ofthe sum of m+n, X₁ is as defined for R₁ or is a group (R₁₅)₃ SiO-- withR₁₅ being C₁ -C₈ alkyl or phenyl, X₂ is hydrogen, C₁ -C₈ alkyl, a group(R₁₅)₃ Si-- or when R₁ and X₁ are C₁ -C₈ alkyl or phenyl, X₂ isadditionally a ##STR10## and, when m+n is a number from 3 to 10, X₁ andX₂ together also form a direct bond.

The compounds of the formula (I) contain structural units of the formula(Ia) or a combination of the formulae (Ia) and (Ib) ##STR11##

When the compounds of the present invention are polymers or copolymers,each of the groups A, R₁, R₂ and R₃ in the individual recurringstructural units (Ia) and (Ib) of the formula (I) can be identical ordifferent.

When the compounds of the present invention are copolymers, the singlestructural units (Ia) and (Ib) of the formula (I) can be distributedtherein at random or in blocks.

Examples of alkyl having not more than 18 carbon atoms are methyl,ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl,2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl,undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl.

Examples of C₂ -C₄ alkyl substituted by C₁ -C₈ alkoxy are2-methoxyethyl, 2-ethoxyethyl, 3-methoxypropyl, 3-ethoxypropyl,3-butoxypropyl, 3-octoxypropyl and 4-methoxybutyl. 3-Methoxypropyl and3-ethoxypropyl are preferred.

Examples of C₂ -C₄ alkyl substituted by di-(C₁ -C₄ alkyl)-amino,preferably by dimethylamino or diethylamino, are 2-dimethylaminoethyl,2-diethylaminoethyl, 3-dimethylaminopropyl, 3-diethylaminopropyl,3-dibutylaminopropyl and 4-diethylaminobutyl.

Examples of C₂ -C₄ alkyl substituted by a group of formula (III) are2-pyrrolidinoethyl, 2-morpholinoethyl, 3-morpholinopropyl,2-piperidinoethyl, 3-piperidinopropyl and 2-(4-methylpiperazino)-ethyl.3-Morpholinopropyl is preferred.

Examples of alkoxy containing not more than 18 carbon atoms are methoxy,ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy,hexoxy, heptoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy,hexadecyloxy and octadecyloxy.

Representative examples of C₅ -C₁₂ cycloalkyl R₆ and R₁₂, which isunsubstituted or mono-, di- or tri-substituted by C₁ -C₄ alkyl, arecyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl,methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl,t-butylcyclohexyl, cyclooctyl, cyclodecyl and cyclododecyl;unsubstituted or C₁ -C₄ alkyl-substituted cyclohexyl is preferred.

Examples of C₅ -C₁₂ cycloalkoxy are cyclopentoxy, cyclohexoxy,cycloheptoxy, cyclooctoxy, cyclodecyloxy and cyclododecyloxy.Cyclopentoxy and cyclohexoxy are preferred.

Examples of C₃ -C₆ alkenyl are allyl, 2-methylallyl, 2-butenyl and2-hexenyl. Allyl is preferred.

Examples of C₇ -C₉ phenylalkyl which is unsubstituted or mono-, di- ortri-substituted on the phenyl by C₁ -C₄ alkyl are benzyl, methylbenzyl,dimethylbenzyl, trimethylbenzyl, t-butylbenzyl and 2-phenylethyl. Benzylis preferred.

Examples of C₁ -C₈ acyl are formyl, acetyl, propionyl, butyryl,pentanoyl, hexanoyl, heptanoyl, octanoyl, benzoyl, acryloyl andcrotonyl. C₁ -C₈ alkanoyl, C₃ -C₈ alkenoyl and benzoyl are preferred.Acetyl is especially preferred.

Representative examples of C₂ -C₁₈ alkanediyl R₅, when p is 1, areethylene, ethylidene, propylene, propylidene, trimethylene,methyltrimethylene, tetramethylene, pentamethylene, hexylene,decamethylene or groups of the formula ##STR12##

Representative examples of C₂ -C₁₂ alkanediyl R₇ are ethylene,trimethylene, methyltrimethylene, tetramethylene, pentamethylene andundecamethylene.

Representative examples of C₁ -C₁₈ alkanediyl R₉ are methylene,ethylene, trimethylene or a linear or branched C₄ -C₁₈ alkanediyl, forexample butylene, pentylene, hexylene, octylene, decylene, dodecylene,tetradecylene, hexadecylene and octadecylene.

C₃ -C₁₂ Alkanediyl R₁₃ is, for example, trimethylene,methyltrimethylene, tetramethylene, pentamethylene, hexamethylene orundecamethylene.

Representative examples of C₂ -C₂₀ alkanetriyl R₅, when p is 2, areethanetriyl, propanetriyl, butanetriyl or a ##STR13## where R_(a) islinear or branched C₃ -C₁₈ alkanediyl, for example trimethylene,butylene, pentylene, hexylene, octylene, decylene, dodecylene,tetradecylene, hexadecylene or octadecylene.

Representative examples of C₅ -C₇ cycloalkanetriyl or C₇ -C₉bicycloalkanetriyl R₅ are the groups ##STR14##

Representative examples of C₃ -C₆ alkanetetrayl R₅ are propanetetrayl,butanetetrayl and pentanetetrayl.

Representative examples of (C₁ -C₈ alkoxy)carbonyl are methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl,isobutoxycarbonyl, pentoxycarbonyl, isopentoxycarbonyl, hexoxycarbonyl,heptoxycarbonyl and octoxycarbonyl.

The preferred definitions of R₄ are hydrogen, C₁ -C₄ alkyl, OH, C₆ -C₁₂alkoxy, C₅ -C₈ cycloalkoxy, allyl, benzyl or acetyl, in particularhydrogen or methyl.

Those compounds of the formula (I) are preferred in which A is one ofthe groups of the formulae (IIa)-(IId) in which X₃ is --O-- or >N--R₁₂where R₁₂ is hydrogen, C₁ -C₁₂ alkyl, C₅ -C₈ cycloalkyl which isunsubstituted or mono-, di- or tri-substituted by C₁ -C₄ alkyl; benzylwhich is unsubstituted or mono-, di- or tri-substituted by C₁ -C₄ alkyl;tetrahydrofurfuryl, C₂ -C₃ alkyl substituted in the 2-or 3-position byC₁ -C₄ alkoxy, by di-(C₁ -C₄ alkyl)-amino or by a 1-pyrrolidyl,1-piperidyl or 4-morpholinyl group, or R₁₂ is a group of the formula(IV) or one of the groups of the formulae (Va)-(Vd) in which X₅ is --O--or >N--CH₃ and X₆ is --CH₂ CH₂ --, --CO-- or --COCO--, or X₃ is a1,4-piperazinediyl group, p is 1, 2 or 3 and, when p is 1, R₅ is C₂ -C₁₂alkanediyl and, when p is 2, R₅ is C₂ -C₁₆ alkanetriyl, C₆ -C₇cycloalkanetriyl, C₇ -C₉ bicycloalkanetriyl or a group ##STR15## whereX₇ is --O-- or >N--R₁₄ with R₁₄ being C₁ -C₆ acyl or (C₁ -C₆alkoxy)carbonyl, R₁₃ is C₃ -C₁₁ alkanediyl and q is zero or 1, and, whenp is 3, R₅ is C₃ -C₄ alkanetetrayl, R₆ is as defined above for R₁₂, R₇is C₂ -C₁₁ alkanediyl, R₈ is hydrogen or methyl, R₉ is a direct bond, C₁-C₁₂ alkanediyl or a group --X₇ --R₁₃ -- with X₇ and R₁₃ as definedabove, R₁₀ is hydrogen or methyl and R₁₁ is --CH₂ --, R₁ is C₁ -C₆alkyl, phenyl, C₁ -C₆ alkoxy or OH, R₂ and R₃ which are identical ordifferent are C₁ -C₆ alkyl or phenyl or R₂ is also hydrogen, m+n is anumber from 1 to 80 and n varies from zero to 90% of the sum m+n, X₁ isas defined for R₁ or is a group (R₁₅)₃ SiO-- with R₁₅ being C₁ -C₆alkyl, X₂ is hydrogen, C₁ -C₆ alkyl, a group (R₁₅)₃ Si-- or, when R₁ andX₁ are C₁ -C₆ alkyl or phenyl, X₂ is additionally a ##STR16## and, whenm+n is a number from 3 to 10, X₁ and X₂ together also form a directbond.

Those compounds of the formula (I) are particularly preferred in which Ais one of the groups of the formulae (IIa)-(IId) in which X₃ is --O-- or>N--R₁₂ where R₁₂ is hydrogen, C₁ -C₁₀ alkyl, cyclohexyl which isunsubstituted or mono-, di- or trisubstituted by C₁ -C₄ alkyl; benzyl,tetrahydrofurfuryl, C₂ -C₃ alkyl substituted in the 2- or 3-position bymethoxy, by ethoxy, by dimethylamino, by diethylamino or by4-morpholinyl, or R₁₂ is a group of the formula (IV) or one of thegroups of the formulae (Va)-(Vd) in which X₅ is --O-- or >N--CH₃ and X₆is --CH₂ CH₂ -- or --CO--, or X₃ is a 1,4-piperazinediyl group, p is 1,2or 3 and, when p is 1, R₅ is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ isC₂ -C₁₄ alkanetriyl, cyclohexanetriyl or bicycloheptanetriyl or a group##STR17## where R₇ is --O-- or >N--R₁₄ with R₁₄ being C₁ -C₄ acyl or (C₁-C₄ alkoxy)carbonyl, R₁₃ is trimethylene and q is zero or 1, and, when pis 3, R₅ is propanetetrayl, R₆ is as defined above for R₁₂, R₇ is C₂-C₁₁ alkanediyl, R₈ is hydrogen or methyl, R₉ is a direct bond, C₁ -C₁₂alkanediyl or a group --X₇ --R₁₃ -- with X₇ and R₁₃ being as definedabove, R₁₀ is hydrogen or methyl and R₁₁ is --CH₂ --, R₁ is C₁ -C₄alkyl, phenyl, C₁ -C₄ alkoxy or OH, R₂ and R₃ which are identical ordifferent are C₁ -C₄ alkyl or phenyl, or R₂ is also hydrogen, m+n is anumber from 1 to 60 and n varies from zero to 90% of the sum m+n, X₁ isas defined for R₁ or is a group (R₁₅)₃ SiO- with R₁₅ being C₁ -C₄ alkyl,X₂ is hydrogen, C₁ -C₄ alkyl, a group (R₁₅)₃ Si- or, when R₁ and X₁ areC₁ -C₄ alkyl or phenyl, X₂ is additionally a ##STR18## and, when m+n isa number from 3 to 10, X₁ and X₂ together also form a direct bond.

Those compounds of the formula (I) are of special interest in which A isa group of the formula (IIa) or (IIb) in which X₃ is --O-- or >N--R₁₂where R₁₂ is hydrogen, C₁ -C₈ alkyl, cyclohexyl, benzyl,tetrahydrofurfuryl, a group of the formula (IV) or a group of theformula (Va) or (Vb) in which X₅ is --O-- or >N--CH₃ and X₆ is --CH₂ CH₂-- or X₃ is a 1,4-piperazinediyl group, p is 1 or 2 and, when p is 1, R₅is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₆ isas defined above for R₁₂, R₇ is C₂ -C₄ alkanediyl, R₁ is C₁ -C₃ alkyl,C₁ -C₃ alkoxy or OH, R₂ and R₃ are C₁ -C₃ alkyl or R₂ is also hydrogen,m+n is a number from 1 to 50 and n varies from zero to 75% of the summ+n, X₁ is as defined for R₁ or is a group (R₁₅)₃ SiO- with R₁₅ being C₁-C₃ alkyl, X₂ is hydrogen, C₁ -C₃ alkyl, a group (R₁₅)₃ Si- or, when R₁and X₁ are C₁ -C₃ alkyl, X₂ is additionally a ##STR19## and, when m+n isa number from 3 to 10, X₁ and X₂ together also form a direct bond.

Those compounds of the formula (I) are of particular interest in which Ais a group of the formula (IIa) or (IIb) in which R₄ is hydrogen ormethyl, X₃ is --O-- or --NH--, p is 1 or 2, and when p is 1, R₅ is C₂-C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₆ ishydrogen, C₁ -C₄ alkyl, 2,2,6,6-tetramethyl-4-piperidyl or1,2,2,6,6-pentamethyl-4-piperidyl and R₇ is trimethylene, R₁ is methyl,methoxy, ethoxy or OH, R₂ and R₃ are methyl, m+n is a number from 1 to40, n varies from zero to 50% of the sum m+n, X₁ is as defined for R₁ oris a group (CH₃)₃ SiO- and X₂ is hydrogen, methyl, ethyl, a group (CH₃)₃Si- or, when R₁ and X₁ are methyl, X₂ is additionally a group ##STR20##and, when m+n is a number from 3 to 10, X₁ and X₂ together also form adirect bond.

In the compounds of the formula (I) A is preferably a group of theformula ##STR21## where R₄ is hydrogen or methyl, X₃ is --O-- or --NH--and R₅ ' is ethylene, propylene or decamethylene.

A further preferred meaning of A is the group of the formula ##STR22##where R₄ is hydrogen or methyl, X₃ is --O-- or --NH-- and R₅ " is agroup --CH₂ --CH< or >CH--(CH₂)₃ --.

An especially preferred meaning of A is the group of the formula##STR23## where R₄ is hydrogen or methyl and R₆ is hydrogen or C₁ -C₄alkyl.

Those compounds of the formula (I) are also of particular interest, inwhich A is a group of the formulae (IIa), (IIb) or (IIc) in which R₄ ishydrogen or methyl, X₃ is --O-- or >N--R₁₂ where R₁₂ is hydrogen or C₁-C₄ alkyl, p is 1 or 2 and, when p is 1, R₅ is C₂ -C₁₀ alkanediyl and,when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₆ is as defined above for R₁₂,R₇ is C₂ -C₄ alkanediyl, R₈ is hydrogen or methyl, R₉ is C₁ -C₁₂alkanediyl, R₁ is C₁ -C₃ alkyl, C₁ -C₃ alkoxy or OH, R₂ and R₃ are C₁-C₃ alkyl or R₂ is also hydrogen, m+n is a number from 1 to 50 and nvaries from zero to 75% of the sum m+n, X₁ is as defined for R₁ or is agroup (R₁₅)₃ SiO- with R₁₅ being C₁ -C₃ alkyl, X₂ is hydrogen, C₁ -C₃alkyl, a group (R₁₅)₃ Si- or, when R₁ and X₁ are C₁ -C₃ alkyl, X₂ isadditionally a ##STR24## and, when m+n is a number from 3 to 10, X₁ andX₂ together also form a direct bond.

The compounds of the present invention can be prepared by diverseprocesses known per se.

Process 1--When m is 1, n is zero, R₁ is C₁ -C₈ alkyl or C₁ -C₈ alkoxy,X₁ is C₁ -C₈ alkyl, C₁ -C₈ alkoxy or a group (R₁₅)₃ SiO- and X₂ is C₁-C₈ alkyl, a group (R₁₅)₃ Si-or a ##STR25## with R₁ and X₁ being C₁ -C₈alkyl or phenyl, the compounds of the formula (I) can be prepared, forexample, in accordance with scheme 1 by reacting an alkene, capable offorming a group A as defined above, with a silane of the formula (VI)##STR26##

The hydrosilylation reaction (see Speier, J.A.C.S. 79, 974, (1957)) isin particular carried out in the presence of a catalytic quantity of Pd,Pt, Rh or derivatives thereof, preferably of Pt and Rh complexes, inparticular H₂ PtCl₆ and the PtCl₂ (Ph--CH═CH₂)₂ complex, operating inthe absence of solvent or in an inert solvent, for exampletetrahydrofuran, dioxane, hexane, heptane, cyclohexane, toluene orxylene, at temperatures between 60° C. and 150° C., preferably between80° C. and 130° C.

Process 2--By total or partial hydrolysis of the compounds of theformula (VII) containing at least one alkoxy group bound to a siliconatom, the corresponding silanol compounds can be prepared, from whichthe corresponding compounds of the formula (I) with m being at least 2and n being zero can be obtained by condensation reactions.

The hydrolysis and condensation reactions are preferably carried outsimultaneously, by treating the compounds of the formula (VII)containing alkoxysilane groups with water in a quantity of at least 0.5mol per alkoxy group in the presence of a catalyst, preferably aninorganic acid, for example HCl, H₂ SO₄ or H₃ PO₄, or an organic acid,for example formic or acetic acid, operating at temperatures between-10° C. and 50° C., preferably between 0° C. and 30° C.

When the hydrolysis/condensation reaction is carried out in the presenceof appropriate quantities of a disiloxane [(R₁₅)₃ Si]₂ O, the compoundsof the formula (I) with m being at least 2 and n being zero, in which X₁is a group (R₁₅)₃ SiO-- and X₂ is a group (R₁₅)₃ Si--, can be obtained.

The hydrolysis/condensation reactions are preferably carried out inwater or in the same solvent as that used for the preparation of thecompounds of the formula (VII).

Process 3--When m is at least 2 and n is other than zero, the compoundsof the formula (I) can be prepared by hydrolysis/condensation ofmixtures in the appropriater ratios of compounds of the formula (VII)and of compounds of the formula (VIII) or (IX) ##STR27## in which R₂ andR₃ are as defined above, R₁₆ is C₁ -C₈ alkoxy and r is 3 or 4, ifdesired in the presence of appropriate quantities of the disiloxane[(R₁₅)₃ Si]₂ O as chain terminator, operating under the conditionsindicated in process 2.

Process 4--Compounds of the formula (I) with m being at least 2 and nbeing equal to or other than zero, can also be prepared by reacting acompound of the formula (X) ##STR28## where X₁, X₂, R₁, R₂ and R₃ are asdefined above, excluding R₂ defined as hydrogen, with appropriatequantities of an alkene capable of forming a group A as defined above,operating as stated under process 1.

In this reaction, it is possible to have a total or partial substitutionof the hydrogen atoms bound to the silicon atoms, but not less than 30%of theory. As mentioned at the outset, the compounds of the formula (I)are highly effective in improving the light stability, heat stabilityand oxidation stability of organic materials, in particular syntheticpolymers and copolymers.

Examples of such organic materials which can be stabilised are:

1. Polymers of monoolefins and diolefins, for example polypropylene,polyisobutylene, polybutene-1, polymethylpentene-1, polyisoprene orpolybutadiene, as well as polymers of cycloolefins, for instance ofcyclopentene or norbornene, polyethylene (which optionally can becrosslinked), for example high density polyethylene (HDPE), low densitypolyethylene (LDPE), linear low density polyethylene (LLDPE), branchedlow density polyethylene (BLDPE).

2. Mixtures of the polymers mentioned under 1), for example mixtures ofpolypropylene with polyisobutylene, polypropylene with polyethylene (forexample PP/HDPE, PP/LDPE) and mixtures of different types ofpolyethylene (for example LDPE/HDPE).

3. Copolymers of monoolefines and diolefines with each other or withother vinyl monomers, such as, for example, ethylene/propylene, linearlow density polyethylene (LLDPE) and its mixtures with low densitypolyethylene (LDPE), propylene/butene-1, ethylene/hexene,ethylene/ethylpentene, ethylene/heptene, ethylene/octene,propylene/isobutylene, ethylene/butene-1, propylene/butadiene,isobutadiene/isoprene, ethylene/alkyl acrylates, ethylene/alkylmethacrylates, ethylene/vinyl acetate copolymers and their copolymerswith carbon monoxide or ethylene/acrylic acid copolymers and their salts(ionomers) and terpolymers of ethylene with propylene and a diene, suchas hexadiene, dicyclopentadiene or ethylidene-norbornene; as well asmixtures of such copolymers and their mixtures with polymers mentionedin 1) above, for example polypropylene/ethylene-propylene-copolymers,LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acidcopolymers (EAA), LLDPE/EVA, LLDPE/EAA and statistical or alternatingpolyalkylene/carbon monoxide-copolymers as well as their mixtures withother polymers, for example polyamide.

3a. Hydrocarbon resins (for example C₅ -C₉) and hydrogenatedmodifications thereof (for example tackyfiers) and mixtures ofpolyalkylenes and starch.

4. Polystyrene, poly-(p-methylstyrene), poly-(α-methylstyrene).

5. Copolymers of styrene or α-methylstyrene with dienes or acrylicderivatives, such as, for example, styrene/butadiene,styrene/acrylonitrile, styrene/alkyl methacrylate, styrene/maleicanhydride, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkylmethacrylate styrene/acrylonitrile/methyl acrylate; mixtures of highimpact strength from styrene copolymers and another polymer, such as,for example, from a polyacrylate, a diene polymer or anethylene/propylene/diene terpolymer; and block copolymers of styrene,such as, for example, styrene/butadiene/styrene,styrene/isoprene/styrene, styrene/ethylene/butylene/styrene orstyrene/ethylene/propylene/styrene.

6. Graft copolymers of styrene or α-methylstyrene such as, for example,styrene on polybutadiene, styrene on polybutadiene-styrene orpolybutadiene-acrylonitrile; styrene and acrylonitrile (ormethacrylonitrile) on polybtuadiene; styrene and maleic anhydride ormaleimide on polybutadiene; styrene, acrylonitrile and maleic anhydrideor maleimide on polybutadiene; styrene, acrylonitrile and methylmethacrylate on polybutadiene, styrene and alkyl acrylates ormethacrylates on polybutadiene, styrene and acrylonitrile onethylene/propylene/diene terpolymers, styrene and acrylonitrile onpolyacrylates or polymethacrylates, styrene and acrylonitrile onacrylate/butadiene copolymers, as well as mixtures thereof with thecopolymers listed under 5), for instance the copolymer mixtures known asABS-, MBS-, ASA- or AES-polymers.

7. Halogen-containing polymers, such as polychloroprene, chlorinatedrubbers, chlorinated or sulfochlorinated polyethylene, copolymers ofethylene and chlorinated ethylene, epichlorohydrin homo- and copolymers,polymers from halogen-containing vinyl compounds, as for example,poly-vinylchloride, polyvinylidene chloride, polyvinyl fluoride,polyvinylidene fluoride, as well as copolymers thereof, as for example,vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate orvinylidene chloride/vinyl acetate copolymers.

8. Polymers which are derived from α,β-unsaturated acids and derivativesthereof, such as polyacrylates and polymethacrylates, with butylacrylate impact resistant modified polymethyl methacrylate,polyacrylamide and polyacrylonitrile.

9. Copolymers from the monomers mentioned under 8) with each other orwith other unsaturated monomers, such as, for instance,acrylonitrile/butadiene, acrylonitrile/alkyl acrylate,acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halogenidecopolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

10. Polymers which are derived from unsaturated alcohols and amines, oracyl derivatives thereof or acetals thereof, such as polyvinyl alcohol,polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinylmaleate, polyvinyl butyral, polyallyl phthalate or polyallylmelamine; aswell as their copolymers with olefins mentioned in 1) above.

11. Homopolymers and copolymers of cyclic ethers, such as polyalkyleneglycols, polyethylene oxide, polypropylene oxide or copolymers thereofwith bis-glycidyl ethers.

12. Polyacetals, such as polyoxymethylene and those polyoxymethyleneswhich contain ethylene oxide as a comonomer; polyacetals modified withthermoplastic polyurethanes, acrylates or MBS.

13. Polyphenylene oxides and sulfides, and mixtures of polyphenyleneoxides with polystyrene or polyamides.

14. Polyurethanes which are derived from polyethers, polyesters orpolybutadienes with terminal hydroxyl groups on the one side andaliphatic or aromatic polyisocyanates on the other side, as well asprecursors thereof (polyisocyanates, polyols or prepolymers).

15. Polyamides and copolyamides which are derived from diamines anddicarboxylic acids and/or from aminocarboxylic acids or thecorre-sponding lactams, such as polyamide 4, polyamide 6, polyamide 6/6,6/10, 6/9, 6/12, 4/6, 12/12 polyamide 11, polyamide 12, aromaticpolyamides obtained by condensation of m-xylene diamine and adipic acid;polyamides prepared from hexamethylenediamine and isophthalic or/andterephthalic acid and optionally an elastomer as modifier, for examplepoly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenyleneisophthalamide. Further copolymers of the aforementioned polyamides withpolyolefins, olefin copolymers, ionomers or chemically bonded or graftedelastomers; or with polyethers, such as for instance, with polyethyleneglycols, polypropylene glycols or polytetramethylene glycols. Polyamidesor copolyamides modified with EPDM or ABS. Polyamides condensed duringprocessing (RIM-polyamide systems).

16. Polyureas, polyimides and polyamide-imides.

17. Polyesters which are derived from dicarboxylic acids and diols and[ch] or from hydroxycarboxylic acids or the corresponding lactones, suchas polyethylene terephthalate, polybutylene terephthalate,poly-1,4-dimethylolcyclohexane terephthalate,poly-[2,2,-(4-hydroxyphenyl)-propane] terephthalate andpolyhydroxybenzoates as well as block-copolyether-esters derived frompolyethers having hydroxyl end groups.

18. Polycarbonates and polyester-carbonates.

19. Polysulfones, polyether-sulfones and polyether-ketones.

20. Crosslinked polymers which are derived from aldehydes on the onehand and phenols, ureas and melamines on the other hand, such asphenol/formaldehyde resins, urea/formaldehyde resins andmelamine/formaldehyde resins.

21. Drying and non-drying alkyd resins.

22. Unsaturated polyester resins which are derived from copolyesters ofsaturated and unsaturated dicarboxylic acids with polyhydric alcoholsand vinyl compounds as crosslinking agents, and also halogen-containingmodifications thereof of low inflammability.

23. Thermosetting acrylic resins, derived from substituted acrylicesters, such as epoxy-acrylates, urethane-acrylates orpolyester-acrylates.

24. Alkyd resins, polyester resins or acrylate resins in admixture withmelamine resins, urea resins, polyisocyanates or epoxide resins ascrosslinking agents.

25. Crosslinked epoxide resins which are derived from polyepoxides, forexample from bis-glycidyl ethers or from cycloaliphatic diepoxides.

26. Natural polymers, such as cellulose, rubber, gelatine andderivatives thereof which are chemically modified in apolymer-homologous manner, such as cellulose acetates, cellulosepropionates and cellulose butyrates, or the cellulose ethers, such asmethylcellulose; rosins and their derivatives.

27. Mixtures of polymers as mentioned above, for example PP/EPDM,Polyamide 6/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS,PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR,PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPE/HIPS, PPE/PA 6.6 andcopolymers, PA/HDPE, PA/PP, PA/PPE.

28. Naturally occurring and synthetic organic materials which are puremonomeric compounds or mixtures of such compounds, for example mineraloils, animal and vegetable fats, oil and waxes, or oils, fats and waxesbased on synthetic esters (e.g. phthalates, adipates, phosphates ortrimellithates) and also mixtures of synthetic esters with mineral oilsin any weight ratios, which materials may be used as plasticizer forpolymers or as textile spinning oils, as well as aqueous emulsions ofsuch materials.

29. Aqueous emulsions of natural or synthetic rubber, e.g. natural latexor latices of carboxylated styrene/butadiene copolymers.

The compounds of the formula (I) are particularly suitable for improvingthe light stability, heat stability and oxidation stability ofpolyolefins, especially polyethylene and polypropylene.

The compounds of the formula (I) can be used in mixtures with organicmaterials in various proportions depending on the nature of the materialto be stabilised, on the end use and on the presence of other additives.

In general, it is appropriate to use, for example, 0.01 to 5% by weightof the compounds of the formula (I), relative to the weight of thematerial to be stabilised, preferably between 0.05 and 1%.

In general, the compounds of the formula (I) can be added to thepolymeric materials before, during or after the polymerisation orcrosslinking of the said materials.

The compounds of the formula (I) can be incorporated in the polymericmaterials in the pure form or encapsulated in waxes, oils or polymers.

The compounds of the formula (I) can be incorporated in the polymericmaterials by various processes, such as dry mixing in the form ofpowder, or wet mixing in the form of solutions or suspensions or also inthe form of a masterbatch; in such operations, the polymer can be usedin the form of powder, granules, solutions, suspensions or in the formof latices.

The materials stabilised with the products of the formula (I) can beused for the production of mouldings, films, tapes, monofilaments,fibers, surface coatings and the like.

If desired, other conventional additives for synthetic polymers, such asantioxidants, UV absorbers, nickel stabilisers, pigments, fillers,plasticisers, antistatic agents, flameproofing agents, lubricants,corrosion inhibitors and metal deactivators, can be added to themixtures of the compounds of the formula (I) with the organic materials.

Particular examples of additives which can be used in mixture with thecompounds of the formula (I) are:

1. Antioxidants

1.1.. Alkylated monophenols, for example2,6-di-tert-butyl-4-methyl-phenol, 2-tert-butyl-4,6-dimethylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol,2,6-di-tert-butyl-4-iso-butylphenol, 2,6-dicyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexyl-phenol,2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-di-nonyl-4-methylphenol,2,4-dimethyl-6-(1'-methyl-undec-1'-yl)-phenol,2,4-dimethyl-6-(1'-methylheptadec-1'-yl)-phenol,2,4-dimethyl-6-(1'-methyl-tridec-1'-yl)-phenol and mixtures thereof.1.2. Alkylthiomethylphenols, for example2,4-dioctylthiomethyl-6-tert-butylphenol,2,4-dioctylthiomethyl-6-methylphenol,2,4-dioctylthiomethyl-6-ethylphenol,2,6-di-dodecylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones, for example2,6-di-tert-butyl-4-methoxy-phenol, 2,5-di-tert-butylhydroquinone,2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,2,6-di-tert-butyl-hydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyphenyl-stearate,bis-(3,5-di-tert-butyl-4-hydroxyphenyl)adipate.

1.4. Hydroxylated thiodiphenyl ethers, for example2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol),4,4'-thiobis(6-tert-butyl-3-methylphenol),4,4'-thiobis(6-tert-butyl-2-methylphenol),4,4'-thio-bis-(3,6-di-sec-amylphenol),4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl)-disulfide.

1.5. Alkylidenebisphenols, for example2,2'-methylenebis(6-tert-butyl-4-methylphenol),2,2'-methylenebis(6-tert-butyl-4-ethylphenol),2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol],2,2'-methylenebis(4-methyl-6-cyclohexylphenol),2,2'-methylenebis(6-nonyl-4-methylphenol),2,2'-methylenebis(4,6-di-tert-butylphenol),2,2'-ethylidenebis(4,6-di-tert-butylphenol),2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2'-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol],4,4'-methylenebis(2,6-di-tert-butylphenol),4,4'-methylenebis(6-tert-butyl-2-methylphenol),1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane,ethylene glycol bis[3,3-bis-(3'-tert-butyl-4'-hydroxyphenyl)butyrate],bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene,bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butan,2,2-bis-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propan,2,2-bis-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercapto-butan,1,1,5,5-tetra-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-pentan.

1.6. O-, N- and S-benzyl compounds, for example3,5,3',5'-tetra-tert.-butyl-4,4'-dihydroxydibenzylether,octadecyl-4-hydroxy-3,5-dimethylbenzyl-mercaptoacetate,tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-amine,bis-(4-tert.-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-sulfide,isooctyl-3,5-di-tert.-butyl-4-hydroxybenzyl-mercaptoacetate.

1.7. Hydroxybenzylated Malonates, for exampledioctadecyl-2,2-bis-(3,5-di-tert.-butyl-2-hydroxybenzyl)-malonate,di-octadecyl-2-(3-tert.-butyl-4-hydroxy-5-methylbenzyl)-malonate,di-dodecylmercaptoethyl-2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate,Di-[4-(1,1,3,3-tetramethylbutyl)-phenyl]-2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate.

1.8. Hydroxybenzyl-Aromatics, for example1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,1,4-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-phenol.

1.9. Triazine Compounds, for example

2,4-bis-octylmercapto-6-(3,5-di-tert.-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-1,3,5-triazine,2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-1,2,3-triazine,1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-isocyanurate,1,3,5-tris-(4-tert.-butyl-3-hydroxy-2,6-dimethylbenzyl)-isocyanurate,2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,1,3,5-tris-(3,5-di-tert.butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine,1,3,5-tris-(3,5-dicyclohexyl-4-hydroxybenzyl)-isocyanurate.

1.10. Benzylphosphonates, for exampledimethyl-2,5-di-tert.-butyl-4-hydroxybenzylphosphonate,diethyl-3,5-di-tert.-butyl-4-hydroxybenzylphosphonate,dioctadecyl-3,5-di-tert.-butyl-4-hydroxybenzylphosphonate,dioctadecyl-5-tert.-butyl-4-hydroxy-3-methylbenzylphosphonate, Ca-saltof the 3,5-di-tert.-butyl-4-hydroxybenzyl-phosphonic acidmonoethylester.

1.11. Acylaminophenols, for example lauric acid 4-hydroxyanilide,stearic acid 4-hydroxyanilide, octylN-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamate.

1.12. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol,1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol,neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethyleneglycol, pentaerythritol, tris(hydroxyethyl)isocyanurate,N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol,3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane.

1.13. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acidwith mono- or polyhydric alcohols, e.g. with methanol, ethanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxalic aciddiamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane.

1.14 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol,1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol,neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethyleneglycol, pentaerythritol, tris(hydroxyethyl)isocyanurate,N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol,3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane.

1.15 Esters of 3,5-di-tert.-butyl-4-hydroxyphenyl acetic acid with mono-or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol,1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol,neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethyleneglycol, pentaerythritol, tris(hydroxyethyl)isocyanurate,N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol,3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane.

1.16. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g.N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylene-diamine,N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)tri-methylene-diamine,N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine.

2. UV absorbers and light stabilisers

2.1. 2-(2'-Hydroxyphenyl)benzotriazoles, for example the 5'-methyl,3',5'-di-tert-butyl, 5'-tert-butyl, 5'-(1,1,3,3-tetramethylbutyl),5-chloro-3',5'-di-tert-butyl, 5-chloro-3'-tert-butyl-5'-methyl,3'-sec-butyl-5'-tert-butyl, 4'-octoxy, 3', 5'-di-tert-amyl and3',5'-bis(α,α-dimethylbenzyl), mixture of5-chloro-3'-tert.-butyl-5'-(2-octyloxycarbonylethyl)- and5-chloro-3'-tert.-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-,5-chloro-3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-,3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-,3'-tert.-butyl-5'-(2-octyloxycarbonylethyl)-,3'-tert.-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-,3'-dodecyl-5'-methyl- and3'-tert.-butyl-5'-(2-isooctyloxycarbonylethyl)-2'-hydroxyphenyl-2H-benztriazole(2),2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benztriazole-2-yl-phenol];product of ester interchange of2-[3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxy-phenyl]-2H-benztriazole with polyethylene glycol 300; [R--CH₂ CH₂ --COO(CH₂)₃]₂ with R=3'-tert.-butyl-4'-hydroxy-5'-2H-benzotriazole-2-yl-phenyl.

2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and2'-hydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of substituted and unsubstituted benzoic acids, as forexample 4-tert.butylphenyl salicylate, phenyl salicylate, octylphenylsalicylate, dibenzoylresorcinol, bis-(4-tert.butylbenzoyl)-resorcinol,benzoylresorcinol, 2,4-di-tert.butylphenyl3,5-di-tert.butyl-4-hydroxybenzoate, hexadecyl3,5-di-tert.butyl-4-hydroxybenzoate, octadecyl3,5-di-tert.-butyl-4-hydroxybenzoate, 2 methyl-4,6-di-tert.-butylphenyl3,5-di-tert.-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctylα-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methylα-cyano-β-methyl-p-methoxy-cinnamate, butylα-cyano-β-methyl-p-methoxy-cinnamate, methylα-carbomethoxy-p-methoxycinnamate andN-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or1:2 complex, with or without additional ligands such as n-butylamine,triethanolamine or N-cyclohexyldiethanolamine, nickeldibutyldithiocarbamate, nickel salts of4-hydroxy-3,5-di-tert-butylbenzyl-phosphonic acid monoalkyl esters, e.g.of the methyl or ethyl ester, nickel complexes of ketoximes, e.g. of2-hydroxy-4-methyl-phenyl undecyl ketoxime, nickel complexes of1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additionalligands.

2.6. Sterically hindered amines, for examplebis(2,2,6,6-tetramethyl-piperidyl)sebacate,bis-(2,2,6,6-tetramethyl-piperidyl)succinate,bis(1,2,2,6,6-pentamethylpiperidyl)sebacate,bis(1,2,2,6,6-pentamethylpiperidyl)n-butyl-3,5-di-tert-butyl-4-hydroxy-benzylmalonate,the condensation product of1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, the condensation product ofN,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-triazine,tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate,1,1'-(1,2-ethanediyl)bis-(3,3,5,5-tetramethylpiperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis-(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert.-butylbenzyl)malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazasprio[4.5]decan-2,4-dion,bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate,bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, product ofcondensation of N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, product ofcondensation of-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis-(3-aminopropylamino)ethane, product of condensation of2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis-(3-aminopropylamino)ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dion,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dion,3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidin-2,5-dion.

2.7. Oxalic acid diamides, for example 4,4'-dioctyloxyoxanilide,2,2'-dioctyloxy-5,5'-di-tert-butyloxanilide,2,2'-didodecyloxy-5,5'-di-tert-butyloxanilide,2-ethoxy-2'-ethyloxanilide, N,N'-bis(3-dimethylamino-propyl)oxalamide,2-ethoxy-5-tert-butyl-2'-ethyloxanilide and its mixture with2-ethoxy-2'-ethyl-5,4'-di-tert-butyloxanilide and mixtures of ortho- andpara-methoxy-disubstituted oxanilides and mixtures of o- andp-ethoxy-disubstituted oxanilides.

2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine.

3. Metal deactivators, for example N,N'-diphenyloxalic acid diamide,N-salicylal-N'-salicyloylhydrazine, N,N'-bis(salicyloyl)hydrazine,N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,3-salicyl-oylamino-1,2,4-triazole, bis(benzylidene)oxalodihydrazide,Oxanilide, isophthalic acid dihydrazide, sebacicacid-bis-phenylhydrazide, N,N'-diacetal-adipinic acid dihydrazide,N,N'-bis-salicyloyl-oxalic acid dihydrazide,N,N'-bis-salicyloyl-thiopropionic acid dihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite,diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite,diiso-decyl pentaerythritol diphosphite, bis(2,4-di-tert.-butylphenyl)pentaerythritol diphosphite,bis-(2,6-di-tert.-butyl-4-methylphenyl)-pentaeryt hritol diphosphite,bis-isodecyloxy-pentaerythritol diphosphite,bis-(2,4-di-tert.-butyl-6-methylphenyl)-pentaerythritol diphosphate,bis-(2,4,6-tri-tert.-butylphenyl)-pentaerythritol diphosphite,tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)4,4'-biphenylene diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert.-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin,6-fluoro-2,4,8,10-tetra-tert.-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin.

5. Peroxide scavengers, for example esters of β-thiodipropionic acid,for example the lauryl, stearyl, myristyl or tridecyl esters,mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zincdibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritoltetrakis(β-dodecyl-mercapto)propionate.

6. Polyamide stabilisers, for example, copper salts in combination withiodides and/or phosphorus compounds and salts of divalent manganese.

7. Basic co-stabilisers, for example, melamine, polyvinylpyrrolidone,dicyandiamide, triallyl cyanurate, urea derivatives, hydrazinederivatives, amines, polyamides, polyurethanes, alkali metal salts andalkaline earth metal salts of higher fatty acids for example Castearate, Zn stearate, Mg behenate, Mg stearate, Na ricinoleate and Kpalmitate, antimony pyrocatecholate or zinc pyrocatecholate.

8. Nucleating agents, for example, 4-tert.butyl-benzoic acid, adipicacid, diphenylacetic acid.

9. Fillers and reinforcing agents, for example, calcium carbonate,silicates, glass fibers, asbestos, talc, kaolin, mica, barium sulfate,metal oxides and hydroxydes, carbon black, graphite.

10. Other additives, for example, plasticisers, lubricants, emulsifiers,pigments, optical brighteners, flameproofing agents, antistatic agentsand blowing agents.

The compounds of the formula (I) can also be used as stabilisers,especially as light stabilisers, for almost all materials known in theart of photographic reproduction and other reproduction techniques ase.g. described in Research Disclosure 1990, 31429 (page 474 to 480).

Several examples of the preparation and use of the compounds of theformula (I) are reported for a more detailed illustration of the presentinvention; these examples are given solely for illustrative purposes anddo not imply any restriction.

The compounds of Examples 1, 4, 11, 12 and 13 are of particularinterest.

EXAMPLE 1

Preparation of the compound of the formula ##STR29##

70 g (0.165 mol) of bis(2,2,6,6-tetramethyl-4-piperidyl) allylmalonate,28.9 g (0.215 mol) of diethoxymethylsilane and 84 mg of PtCl₂(PhCH═CH₂)₂ are heated for 2 hours at 90° C. and for 2 hours at 120° C.in a closed glass reactor. After cooling to 80° C., the excessdiethoxymethylsilane is removed at this temperature in vacuo (21 mbar).The residue is dissolved in 180 ml of a 2:1 (by volume)tetrahydrofuran/n-hexane mixture, and the solution is filtered oversilica gel. After evaporation of the solvent mixture in vacuo, alight-coloured viscous oil is obtained.

    ______________________________________                                        Calculated:                                                                            C = 62.55%; H = 10.14%; N = 5.03%                                    Found:   C = 62.24%; H = 10.04%; N = 5.08%                                    ______________________________________                                    

EXAMPLE 2

Following the procedure described in Example 1, using 115 g (0.255 mol)of bis(1,2,2,6,6-pentamethyl-4-piperidyl) allylmalonate, 44.5 g (0.331mol) of diethoxymethylsilane and 100 mg of PtCl₂ (PhCH═CH₂)₂, thecompound of the formula ##STR30## is prepared as a light-colouredviscous oil.

    ______________________________________                                        Calculated:                                                                            C = 63.65%; H = 10.34%; N = 4.79%                                    Found:   C = 63.58%; H = 10.29%; N = 4.81%                                    ______________________________________                                    

EXAMPLE 3

Preparation of the compound of the formula ##STR31##

50.1 g (0.169 mol) of allylN-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)-carbamate, 29.4 g (0.219mol) of diethoxymethylsilane and 50 mg of PtCl₂ (Ph--CH═CH₂)₂ are heatedfor 2 hours at 90° C. and for 2 hours at 120° C. in a closed glassreactor. The excess diethoxymethylsilane is removed at 80° C. in vacuo(21 mbar), and the product is separated off by distillation: boilingpoint 172°-174° C./0.1 mbar.

    ______________________________________                                        Calculated:                                                                            C = 61.35%; H = 10.77%; N = 6.50%;                                   Found:   C = 60.85%; H = 10.68%; N = 6.46%                                    ______________________________________                                    

EXAMPLES 4-10

Following the procedure described in Example 3 and using the appropriatereagents, the following compounds are obtained:

    __________________________________________________________________________    Example                                                                            Formula                   Boiling point (°C./mbar)                __________________________________________________________________________          ##STR32##                200-202/0.08                                   5                                                                                   ##STR33##                283-285/1000                                   6                                                                                   ##STR34##                222-224/0.3                                    7                                                                                   ##STR35##                195-197/0.05                                   8                                                                                   ##STR36##                190-192/0.1                                    9                                                                                   ##STR37##                resin (purified by chromatography)             10                                                                                  ##STR38##                resin (purified by chromatography)                   ##STR39##                                                               __________________________________________________________________________

EXAMPLE 11

Preparation of a polysiloxane containing recurring units of the formula##STR40##

13.5 g (0.024 mol) of the product from Example 1 are dissolved in 102 mlof 1N HCl and the solution is stirred for 8 hours at ambienttemperature. 100 ml of dichloromethane are added, and the mixture isneutralised with 102 ml of 1N NaOH. The organic layer is separated off,washed with water, dried over anhydrous Na₂ SO₄ and evaporated in vacuo.

The product obtained melts at 32°-34° C. and has a molecular weight ofMn=1800.

EXAMPLE 12

Following the procedure described in Example 11 and using the productfrom Example 2, a polysiloxane containing recurring units of the formula##STR41## is obtained as a light-coloured dense oil of molecular weightMn=2100.

EXAMPLE 13

Following the procedure described in Example 11 and using the compoundfrom Example 3, a polysiloxane containing recurring units of the formula##STR42## is obtained as a light-coloured dense oil of molecular weightMn=1700.

EXAMPLE 14

Following the procedure described in Example 11 and using the productfrom Example 4, a polysiloxane containing recurring units of the formula##STR43## is obtained as a light-coloured dense oil of molecular weightMn=2000.

EXAMPLE 15

Following the procedure described in Example 11 and using the productfrom Example 5, a polysiloxane containing recurring units of the formula##STR44## is obtained as a light-coloured dense oil of molecular weightMn=1000.

EXAMPLE 16

Following the procedure described in Example 11 and using the productfrom Example 6, a polysiloxane containing recurring units of the formula##STR45## is obtained as a light-coloured dense oil of molecular weightMn=1900.

EXAMPLE 17

Following the procedure described in Example 11 and using the productfrom Example 7, a polysiloxane containing recurring units of the formula##STR46## is obtained as a light-coloured dense oil of molecular weightMn=2600.

EXAMPLE 18

Following the procedure described in Example 11 and using the productfrom Example 8, a polysiloxane containing recurring units of the formula##STR47## is obtained as a light-coloured dense oil of molecular weightMn=2000.

EXAMPLE 19

Following the procedure described in Example 11 and using the productfrom Example 9, a polysiloxane containing recurring units of the formula##STR48## is obtained as a white wax of molecular weight Mn=2000.

EXAMPLE 20

Following the procedure described in Example 11 and using the productfrom Example 10, a polysiloxane containing recurring units of theformula ##STR49## is obtained as a light-coloured dense oil of molecularweight Mn=1950.

EXAMPLE 21

Preparation of a polysiloxane containing recurring units of the formulae##STR50##

12.9 g (0.03 mol) of the product from Example 3 and 4.2 g (0.031 mol) ofmethyldicthoxysilane are dissolved in 100 ml of 1,2-dimethoxyethane. 2.8ml of concentrated HCI (37% w/w) are added and the mixture is stirred 4h at room temperature. The mixture is then neutralized with 40 ml of 1NNaOH and evaporated in vacuo (90° C./1.3 mbar).

The residue is dissolved in 100 ml of CH₂ CH₂, washed with water untilneutralization, dried over anhydrous Na₂ SO₄ and evaporated in vacuo(80° C./1.3 mbar).

A light-coloured dense oil of Mn=1970 is obtained.

In the examples, the number-average molecular weight is determined bymeans of a vapour pressure osmometer (®Gonotec) as described inEP-A-255,990, page 18, line 54, to page 19, line 15.

EXAMPLE 22

(light-stabilising action in polypropylene fibres): 2.5 g of each of theproducts indicated in Table 1, 1.0 g of a tris(2,4-di-t-butylphenyl)phosphite, 0.5 g of calcium monoethyl3,5-di-t-butyl-4-hydroxybenzylphosphonate, 1 g of calcium stearate and2.5 g of titanium dioxide are mixed in a slow mixer with 1000 g ofpolypropylene powder of melt index=12 g/10 minutes (measured at 230° C.and 2.16 kg).

The mixtures are extruded at 200°-230° C. to give polymer granules whichare then converted into fibres using a pilot-type apparatus(®Leonard-Sumirago (VA), Italy) and operating under the followingconditions:

    ______________________________________                                        Extruder temperature:                                                                             200-230° C.                                        Head temperature:   255-260° C.                                        Stretch ratio:      1:3.5                                                     Count:              11 dtex per filament                                      ______________________________________                                    

The fibres thus prepared are exposed, mounted on a white card, in amodel 65 WR Weather-O-Meter (ASTM D 2565-85) with a black paneltemperature of 63° C.

The residual tenacity is measured on samples taken after various timesof exposure to light by means of a constant-speed tensometer, and theexposure time in hours (T₅₀) needed to halve the initial tenacity isthen calculated.

Fibres prepared under the same conditions as indicated above, butwithout addition of the compounds of the invention, are exposed forcomparison.

The results obtained are shown in Table 1:

                  TABLE 1                                                         ______________________________________                                        Stabiliser          T.sub.50 (hours)                                          ______________________________________                                        None                 150                                                      Compound from Example 11                                                                          1350                                                      Compound from Example 12                                                                          1120                                                      Compound from Example 13                                                                          1330                                                      ______________________________________                                    

EXAMPLE 23

light-stabilising action in polypropylene tapes): 1 g of each of thecompounds indicated in Table 2, 1.0 g of tris-(2,4di-t-butyl-phenyl)phosphite, 0.5 g of pentaerythritoltetrakis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and 1 g ofcalcium stearate are mixed in a slow mixer with 1000 g of polypropylenepowder of melt index=2g/10 minutes (measured at 230° C. and 2.16 kg).

The mixtures are extruded at 200°-230° C. to give polymer granules whichare then converted into stretched tapes of 50 μm thickness and 2.5 mmwidth, using a pilot-type apparatus (®Leonard-Sumirago (VA), Italy)operating under the following conditions:

    ______________________________________                                        Extruder temperature: 210-230° C.                                      Head temperature:     240-260° C.                                      Stretch ratio:        1:6                                                     ______________________________________                                    

The tapes thus prepared are exposed, mounted on a white card, in a model65 WR Weather-O-Meter (ASTM D 2565-85) with a black panel temperature of63° C.

The residual tenacity is measured on samples taken after various timesof exposure to light by means of a constant-speed tensometer; theexposure time (in hours) (T₅₀) needed to halve the initial tenacity isthen calculated.

Tapes prepared under the same conditions as indicated above, but withoutaddition of stabiliser, are exposed for comparison.

                  TABLE 2                                                         ______________________________________                                        Stabiliser          T.sub.50 (hours)                                          ______________________________________                                        None                 300                                                      Compound of Example 11                                                                            3200                                                      Compound of Example 12                                                                            3180                                                      ______________________________________                                    

EXAMPLE 24

(light-stabilising action in polypropylene plaques): 1 g of each of thecompounds indicated in Table 3, 1.0 g oftris-(2,4-di-t-butylphenyl)phosphite, 0.5 g of pentaerythritoltetrakis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate], 1 g of BluePhthalocyanine and 1 g of calcium stearate are mixed in a slow mixerwith 1000 g of polypropylene powder of melt index=2.1 g/10 minutes(measured at 230° C. and 2.16 kg).

The mixtures are extruded at 200°-220° C. to give polymer plaques of 2mm thickness by injection-moulding at 190°-230° C.

The plaques are then exposed in a Weather-O-Meter 65 WR (ASTM G 26-77)with a black panel temperature of 63° C. until the start of superficialembrittlement (chalking).

For comparison, a polypropylene plaque prepared under the sameconditions as indicated above, but without the addition of the compoundsof the invention, is exposed.

Table 3 shows the exposure time (hours) required to reach the start ofsuperficial embrittlement.

                  TABLE 3                                                         ______________________________________                                        Stabiliser        Embrittlement time (hrs)                                    ______________________________________                                        None               500                                                        Compound of Example 1                                                                           3560                                                        Compound of Example 4                                                                           3980                                                        ______________________________________                                    

What is claimed is:
 1. A compound of the formula (I) ##STR51## in which A is a group of formula (IIa) ##STR52## in which R₄ is hydrogen, C₁ -C₈ alkyl, O.,OH, NO, CH₂ CN, C₁ -C₁₈ alkoxy, C₅ -C₁₂ cycloalkoxy, C₃ -C₆ alkenyl, C₇ -C₉ phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁ -C₄ alkyl; or C₁ -C₈ acyl, X₃ is --O--,p is 1, 2 or 3 and, when p is 1, R₅ is C₂ -C₁₈ alkanediyl and, when p is 2, R₅ is C₂ -C₂₀ alkanetriyl, C₅ -C₇ cycloalkanetriyl or C₇ -C₉ bicycloalkanetriyl or a group ##STR53## where X₇ is --O-- R₁₃ is C₃ -C₁₂ alkanediyl and q is 0 or 1, and, when p is 3, R₅ is C₃ -C₆ alkanetetrayl, R₁ is C₁ -C₈ alkyl, phenyl, C₁ -C₈ alkoxy or OH, R₂ and R₃ which are identical or different are C₁ -C₈ alkyl or phenyl, or R₂ is also hydrogen, m+n is a number from 1 to 100, n varies from zero to 90% of the sum of m+n, X₁ is as defined for R₁ X₂ is hydrogen or C₁ -C₈ alkyl, and, when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond; each of the groups R₁, R₂, R₃ and A have the same definition or different definitions in the recurring structural units contained in formula (I) and, when the compounds of the formula (I) are copolymeric, they have a random distribution or a block distribution of the individual structural units.
 2. A compound of the formula (I) according to claim 1, in which R₄ is hydrogen, C₁ -C₄ alkyl, OH, C₆ -C₁₂ alkoxy, C₅ -C₈ cycloalkoxy, allyl, benzyl or acetyl.
 3. A compound of the formula (I) according to claim 1, in which A is a group of formula (IIa) in which X₃ is --O--, p is 1, 2 or 3 and, when p is 1, R₅ is C₂ -C₁₂ alkanediyl and, when p is 2, R₅ is C₂ -C₁₆ alkanetriyl, C₆ -C₇ cycloalkanetriyl, C₇ -C₉ bicycloalkanetriyl or a group ##STR54## where X₇ is --O--, R₁₃ is C₃ -C₁₁ alkanediyl and q is zero or 1, and, when p is 3, R₅ is C₃ -C₄ alkanetetrayl, R₁ is C₁ -C₆ alkyl, phenyl, C₁ -C₆ alkoxy or OH, R₂ and R₃ which are identical or different are C₁ -C₆ alkyl or phenyl or R₂ is also hydrogen, m+n is a number from 1 to 80 and n varies from zero to 90% of the sum m+n, X₁ is as defined for R₁, X₂ is hydrogen or C₁ -C₆ alkyl, and, when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond.
 4. A compound of the formula (I) according to claim 1, in which A is a group of formula (IIa) in which X₃ is --O--, p is 1, 2 or 3 and, when p is 1, R₅ is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, cyclohexanetriyl or bicycloheptanetriyl or a group ##STR55## where R₇ is --O--, R₁₃ is trimethylene and q is zero or 1, and, when p is 3, R₅ is propanetetrayl, R₁ is C₁ -C₄ alkyl, phenyl, C₁ -C₄ alkoxy or OH, R₂ and R₃ which are identical or different are C₁ -C₄ alkyl or phenyl, or R₂ is also hydrogen, m+n is a number from 1 to 60 and n varies from zero to 90% of the sum m+n, X₁ is as defined for R₁, X₂ is hydrogen or C₁ -C₄ alkyl, and, when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond.
 5. A compound of the formula (I) according to claim 1, in which A is a group of the formula (IIa) in which X₃ is --O--, p is 1 or 2 and, when p is 1, R₅ is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₁ is C₁ -C₃ alkyl, C₁ -C₃ alkoxy or OH, R₂ and R₃ are C₁ -C₃ alkyl or R₂ is also hydrogen, m+n is a number from 1 to 50 and n varies from zero to 75% of the sum m+n, X₁ is as defined for R₁, X₂ is hydrogen or C₁ -C₃ alkyl, and, when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond.
 6. A compound of the formula (I) according to claim 1, in which A is a group of the formula (IIa) in which R₄ is hydrogen or methyl, X₃ is --O--, p is 1 or 2, and when p is 1, R₅ is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₁ is methyl, methoxy, ethoxy or OH, R₂ and R₃ are methyl, m+n is a number from 1 to 40, n varies from zero to 50% of the sum m+n, X₁ is as defined for R₁ and X₂ is hydrogen, methyl or ethyl, and, when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond.
 7. A compound of the formula (I) according to claim 1, in which A is a group of the formula ##STR56## where R₄ is hydrogen or methyl, X₃ is --O--and R₅ ' is ethylene, propylene or decamethylene.
 8. A compound of the formula (I) according to claim 1, in which A is a group of the formula ##STR57## where R₄ is hydrogen or methyl, X₃ is --O--and R₅ " is a group --CH₂ --CH<or >CH--(CH₂)₃ --.
 9. A compound of the formula (I) according to claim 1, in which A is a group of the formulae (IIa) in which R₄ is hydrogen or methyl, X₃ is --O--, p is 1 or 2 and, when p is 1, R₅ is C₂ -C₁₀ alkanediyl and, when p is 2, R₅ is C₂ -C₁₄ alkanetriyl, R₁ is C₁ -C₃ alkyl, C₁ -C₃ alkoxy or OH, R₂ and R₃ are C₁ -C₃ alkyl or R₂ is also hydrogen, m+n is a number from 1 to 50 and n varies from zero to 75% of the sum m+n, X₁ is as defined for R₁ , when m+n is a number from 3 to 10, X₁ and X₂ together also form a direct bond.
 10. A compound according to claim 1, which is ##STR58##
 11. A compound of the formula (I) according to claim 1, in which n is zero and the repeating structural unit of the formula ##STR59##
 12. A composition comprising a synthetic polymer susceptible to degradation induced by light, heat and oxidation and an effective thermal oxidative and light induced stabilizing amount of a compound of the formula (I) according to claim
 1. 13. A composition according to claim 12, in which the synthetic polymer is a polyolefin.
 14. A composition according to claim 12, in which the synthetic polymer is polyethylene or polypropylene.
 15. A method for stabilizing a synthetic polymer against degradation induced by light, heat and oxidation, which comprises incorporating into said organic material an effective stabilizing amount of a compound of the formula (I) according to claim
 1. 